An International team of scientists watched the largest-known star in the universe "breathing its last breaths."
The researchers watched the massive star throwing out its final layers. The observations are a "vital step in understanding how massive stars return enriched material to the interstellar medium - the space between stars - which is necessary for forming planetary systems," a Royal Astronomical Society news release reported.
Larger stars have shorter and more dramatic lives than their smaller peers. Some of the hugest stars lived for only a few million years before running out of fuel and exploding as a supernova.
At the end of their lives, these stellar giants become "highly unstable" and spit out a massive amount of material.
"This material has been enriched by nuclear reactions deep within the star and includes many of the elements necessary for forming rocky planets like our Earth, such as silicon and magnesium, and which are also the basis for life. How this material is ejected and how this affects the evolution of the star is however still a mystery," the news release stated.
The team used the European Southern Observatory's Very Large Telescope Survey Telescope (VST) to discover the most massive star cluster in our galaxy, called Westerlund 1.
The cluster is home to hundreds of thousands of stars and is the closest researchers have come to looking at even more massive clusters in distant galaxies.
The cluster is around 16,000 away from Earth and can be seen in the constellation Ara (The Altar).
The team noticed a cloud of glowing-green hydrogen gas surrounding a star dubbedW26. "Such glowing clouds are ionised, meaning that the electrons have been stripped away from the atoms of hydrogen gas," the news release reported.
This type of cloud is almost never found near a red supergiant like W26, in fact this is the first time scientists have seen anything like it.
Since W26 is most likely not hot enough to create the glow itself, the researchers suggested the source of the light could be a nearby "hot blue star" or a hotter "companion star."
The team noticed the star was most likely the largest ever discovered, having a radius 1,500 times larger than the Sun. The team believes the star is on its last legs.
"The nebula observed around W26 is very similar to the nebula surrounding SN1987A, the remnant of a star that exploded as a supernova in 1987. SN1987A was the closest observed supernova to Earth since 1604 and as such it gave astronomers a chance to better study the properties of these explosions. Studying objects like the new nebula around W26 will help astronomers to understand the mass loss processes around these massive stars, which eventually lead to their explosive demise," the news release reported.
